Valve assemblies for aerosol containers

ABSTRACT

An aerosol container, of the type having a hollow body secured inside the container which cooperates with an elongate valve member operative from outside the container to dispense a predetermined amount only of the contents of the container for each operation, is provided with a second hollow body movable with the valve member and enclosing the first hollow body to form a capillary gap between the two bodies. Provided the container is left in the inverted, dispensing position, the liquid contents are drawn up through the gap by capillary action to fill the inside of the first hollow body ready for dispensing. In this way the container can be virtually completely emptied, minimizing wastage of the contents. The dispensing operation involves a pumping action urging the liquid up through the capillary gap into the first hollow body.

United States Patent [1 1 Wilmot 5] Apr. 17, 1973 [54] VALVE ASSEMBLIES FOR AEROSOL I FOREIGN PATENTS OR APPLICATIONS CONTAINERS 1,194,379 5/1959 France, ..222 402.2 [75] Inventor: Kenneth Wilmot, Clitheroe, England Primary Examzner-Samuel F. Coleman Asslgneel Neotechnic Engineering Limited, Assistant ExaminerH. Grant Skaggs, Jr.

Lancashire, England Attorney-Irvin S. Thompson et al. [22] Filed: May 12, 1972 [57] ABSTRACT [21] APPLNOJ 252898 An aerosol container, of the type having a hollow body Secured inside the container which cooperates 52 US. (:1 ..222/402.2 with an elongate valve member operative from Outside [51] Int. Cl. ..B65d 83/00 the container to dispense a predetermined amount 58 Field or Search ..222/402.1, 402.2 9 the E the each 1 tron, 15 provided with a second hollow body movable Rate nces Cited with the valve member and enclosing the first hollow re body to form a capillary gap between the two bodies. UNITED STATES PATENTS Provided the container is left in the inverted, drspensmg position, the liquid contents are drawn up 3,104,785 9/1963 Beard ..222 402.2 through the gap by capillary action to fill the inside of 1,418 1970 nus win/4021 the first hollow body ready for dispensing. In this way Ward the container can be virtually completely emptied 2,781,954 2/1957 Bretz .....222/402.2 minimizing wastage of the contents. The dispensing 2,886,217 5/ I959 Th1el ..222/402.2 Operation involves a pumping action urging the liquid up through the capillary gap into the first hollow body.

PATENTED APR 1 7 I973 SHEET 1 [IF 2 VALVE ASSEMBLIES FOR AEROSOL CONTAINERS FIELD AND SUMMARY OF THE INVENTION This invention relates to valve assemblies for aerosol containers, and more particularly to those in which a hollow body secured inside the container cooperates with an elongate valve member operative from outside the container to dispense a predetermined amount only I of the contents of the container for each operation.

It is an advantage with many types of aerosol container, including the type of present interest, that it is often difficult or impossible to completely empty the container during use, leading to wastage of a certain proportion of the contents. Containers of the type of present interest are usually used to dispense expensive substances such as cosmetic and medical preparations, and the problem of wastage is thus particularly aggravating, as the loss of even a very small portion of the contents can be extremely costly, especially in the case of certain medical and medico-surgical preparations.

It is accordingly an object of the present invention to provide a valve assembly for an aerosol container in which wastage of the contents of a container to which it is fitted is minimized by allowing virtually complete emptying.

According to the present invention, a valve assembly comprises a casing member adapted to form at least the top portion of an aerosol container, a hollow body secured to the inside of said casing member, an elongate valve member sealingly extending through respective' apertures in the casing member and hollow body for longitudinally inward movement during a dispensing operation from an outer position with respect to the casing member, outlet and inlet passages formed in the valve member adjacent to the outer and inner ends thereof, respectively, and operative for connecting a chamber formed by the space inside the hole low body around the valve member with the outside and inside, respectively, of the container and arranged such that in the outer position only the inlet passage is operative and such that when the valve member is moved by more than a predetermined amount inwardly the inlet passage becomes non-operative and the outlet passage becomes operative, a second hollow body having one end closed and secured to the inner end of the valve member, the second hollow body enclosing the first hollow body and forming a capillary gap between the two bodies which, in the outer position, extends along the first hollow body from near the position where it is secured to the casing member to the aperture therein, whereby the inlet passage in the valve member, in such position, communicates the chamber with the inside of the container via the capillary gap.

When the container with which the valve assembly is used is nearly empty, it is inverted, i.e. disposed in its normal dispensing position, and the liquid contents are drawn up through the capillary gap, through the second passage and into the chamber inside the first hollow body, ready for dispensing. As the capillary gap extends up from near where the first hollow body is secured to the casing member, i.e. the bottom of the container when it is inverted, virtually all of the contents can be drawn up through the capillary gap and wastage is minimized. To minimize even further the very small amount that is wasted, the first hollow body is desirably secured to an outwardly extending portion of the casing member of reduced area.

During a dispensing operation, the increase in the volume of the space between the first and second hollow bodies, which takes place as the valve member and the second hollow body move inwardly, causes the liquid contents of the container, provided the container is inverted, to be drawn in through the capillary gap to fill the space. When the outward movement takes place, the said space decreases in volume and the liquid therein is pumped through the second passage into the chamber. Preferably, the stroke of the longitudinal movement of the second hollow body during a dispensing operation and the internal area of the second hollow body are such that during dispensing the increased space defined between the first and second bodies is at least of the same order of volume as the chamber, whereby liquid drawn through the capillary gap and into the increased space during inward movement of the second hollow body will be urged into the chamber and fill at least the major portion of the chamber upon outward movement of the second hollow body.

Provision of the second hollow body gives rise to the further advantage that, as it occupies a somewhat greater area than the elongate valve member, as it must do to enclose the first hollow body, it produces greater agitation of the contents of the container than would the valve member alone, were the second hollow body not provided. As the contents of the container are often medical preparations suspended in a propellant, agitation of the contents is desirable to ensure correct concentration of the sprayed dose dispensed.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more readily understood from the following detailed description, given by way of example only, of an exemplary embodiment thereof, having reference to the accompanying drawings, in which:

FIG. 1 is an axial sectional view of an aerosol container incorporating a valve assembly in accordance with the present invention, the valve assembly being shown in the outer, non-operative position; and

FIG. 2 is a view corresponding to FIG. 1 but showing the valve in the operative position.

DESCRIPTION OF THE PREFERRED EMBODIMENT The illustrated aerosol container comprises a cap portion 10 having a downwardly extending flange portion 11 attached, e.g. by swaging or rolling, to a main body portion 12 of the container. A tight seal between the cap 10 and the container body 12 is ensured by.the provision of a sealing washer 13 which is clamped between the cap 10 and the body 12.

A longitudinally outwardly extending portion 14 of the cap 10 of smaller area than the rest of the cap has an aperture 15 in the center thereof. A generally cylindrical hollow body 16 is secured inside the portion 14, an outwardly directed flange 17 on the outward end of the body 16 being held in place by an inwardly swaged part 18 of the portion 14 and by a resilient sealing diaphragm 19 which is entrapped between the body 16 and a circular inward deformation 20 of the top of the portion 14 of the cap 10.

An elongate valve stem 22 extends through the aperture in the portion 14 and through an aperture 23 in the inward end of the hollow body 16. The diaphragm 19 and a sealing washer 24 seal the passage of the valve stem 22 through the apertures 15 and 23, respectively, the washer 24 only fully sealing passage of the stem when the stem has been moved inwards sufficiently far towards the FIG. 2 position such that an axial groove 32 in the surface of the stem does not pass through the washer. A helical coil spring 15 which acts against a shoulder 26 on the valve stem 22 at one end, and against the sealing washer 24 at the other end, biases the valve 22 into the outer position shown in FIG. 1. The spring 25 serves to hold the washer 24 in position.

The valve stem 22 is provided at the outer end with an outlet passage 28 for communicating a chamber 29 defined between the hollow body 16 and the valve stem 22 with the outside of the container. The outlet passage 28 comprises an axial part 30 in communication with a radial part 31. The stem 22 is also provided at the inner end with an inlet passage consisting of the groove 32 in the surface thereof extending part of the way outwardly from the inner end. The stem 22 also has fitted to its outer end an operating knob 33. The knob 33 has a passage 34 communicating with the outlet passage 28 in the duct 22, whereby the dispensed contents of the container can be directed where required.

A second generally cylindrical body 36 is secured to the inner end of the valve stem 22 by means of a portion of reduced diameter 37 which is an interference fit thereon. The inside of the hollow member 36 is of the same configuration as the outside of the first-mentioned hollow body 16 whereby a capillary gap is formed between the two, the gap extending inwardly from a flange 38 at the outer end of the body 36 to the aperture 23 in the end closure of the hollow body 16. In the inoperative position of FIG. 1, the flange 38 is spaced apart from a radial flange portion 39 of the ho]- low body 16 which joins the main cylindrical portion and the outwardly axially directed flange 17.

The flange portion 39 has three equally spaced holes 40 therethrough, two of which can be seen in the drawing. These holes 40, which are not essential to the present invention, are provided for the pressure filling of the container. The manner in which the container is filled using the holes 40 is fully described in our copending U.K. Patent application Ser. No. 50240/69: suffice it to say for present purposes that when the container is to be filled, the valve stem 22 is moved inwardly to the FIG. 2 position and a source of the con tents under pressure is communicated to the inlet passage 28, whereupon the diaphragm l9 deforms outwardly into the domed recess at the top of the portion 14 of the cap 10 to allow passage of fluid from the source outwardly through the radial part 31 of the outlet passage and-inwardly through the holes 40 into the container.

The illustrated container is operative to dispense metered shots of the contents, each shot being of a predetermined volume comprising the liquid contents stored within the chamber 29, as follows. Starting from the position of FIG. 1 and assuming that the chamber 29 is full, the container is inverted into its dispensing disposition and the operating knob 33 is depressed whereby the various parts of the valve-assembly take up the positions shown in FIG. 2. During such movement, the outlet passage 28 in the stem 22, which previously only communicated atmosphere to atmosphere, connects the chamber 29 to atmosphere via the conduit 34 in the knob 33. The inlet passage 32, which previously communicated the capillary gap and thus the container with the chamber 29, is isolated from the chamber 29. Consequently, the liquid in the chamber 29 boils and is dispensed as an aerosol spray from the conduit 34. Once the contents of the chamber 29 have been dispensed, no further aerosol spray emerges from the container. The knob 33 is then released and the spring 25 causes the various parts to return to the configuration of FIG. 1.

During the dispensing operation, as the container is inverted the liquid contents of the container are drawn up through the capillary gap between the hollow bodies 16 and 36 and into the space 42 between them, due to the pumping action caused by the formation of this space during the inward movement of the valve stem 22 from the position of FIG. 1 to the position of FIG. 2. The knob 33 is arranged such that the stroke of the movement, coupled with the internal area of the hollow body 36, are such that the space 42 is of the same order of volume as the chamber 29. When the knob 33 is released so that the various parts of the valve assembly move towards the position of FIG. 1, the groove 32 communicates the space 42 and the chamber 29 and the liquid stored in the space 42 enters and fills the chamber.

If the chamber 29 was not filled in the above manner during the previous dispensing operation, it can be filled by simply leaving the container in the inverted position, whereupon capillary attraction will cause the liquid contents to be drawn up through the capillary gap and along the groove 32 into the chamber 29 until.

the chamber is full. It will be apparent that as the entrance to the capillary gap is at the very bottom of the container when it is inverted, virtually the very last drop of the contents can be used, substantially the only wastage being the very small amount trapped in the capillary gap after the last dose has been sprayed.

Various modifications of the valve assembly described above are possible within the scope of the present invention. For example, although, with the exception of the coil spring 25 and the various sealing components, the valve parts are normally made of stainless steel, it is possible for at least the outer hollow body 36 to be made of nylon.

It will also be appreciated that the passages in the valve stem to not have to take exactly the form shown. For instance, the single groove 32 forming the inlet passage could be replaced by a series of grooves spaced around the valve 22 or even by reducing the diameter of the inner end portion of the stem 22 to form an annular passage, provided, in the latter case, that means are provided for guiding the valve stem 22 during its travel.

I claim: I

1. A valve assembly comprising a casing member adapted to form at least the top portion of an aerosol container, a hollow body secured to the inside of said casing member, an elongate valve member sealingly extending through respective apertures in said casing member and said hollow body for longitudinally inward movement during a dispensing operation from an outer position with respect to the casing member, means defining outlet and inlet passages in said valve member adjacent to the outer and inner ends thereof, respectively, and operative for connecting a chamber formed by the space inside said hollow body around said valve member with the outside and inside, respectively, of said container and arranged such that in said outer position only the inlet passage is operative and such that when said valve member is moved by more than a predetermined amount inwardly the inlet passage becomes non-operative and the outlet passage becomes operative, a second hollow body having one end closed and secured to the inner end of said valve member, said second hollow body enclosing said first hollow body and forming a capillary gap between the two bodies which, in said outer position, extends along said first hollow body from near the position where it is secured to said casing member to said aperture therein, whereby said inlet passage in the valve member, in such position, communicates said chamber with the inside of said container via said capillary gap.

2. The valve assembly defined in claim 1 wherein said first hollow body has a cylindrical external configuration and said second hollow body has a cylindrical internal configuration whereby said capillary gap includes an elongate annular portion.

3. The valve assembly defined in claim 2 wherein said valve member is arranged coaxially with said first and second hollow bodies and said aperture in said first hollow body is located centrally of an inner end closure.

4. The valve assembly defined in claim 3 wherein said second hollow body has a portion of reduced diameter at the inner end thereof inside which said inner end of said valve member is fitted.

5. The valve assembly defined in claim 1 including means defining the stroke of said longitudinal movement of said second hollow body during a dispensing operation, said stroke and the internal area of said second hollow body being such that during dispensing the increased space defined between said first and second bodies is at least of the same order of volume as said chamber, whereby liquid drawn through said capillary gap and into said increased space during inward movement of said second hollow body will be urged into said chamber and fill at least the major portion of the chamber upon outward movement of said second hollow body.

6. The valve assembly defined in claim 1 wherein said first hollow body is secured to an outwardly extending portion of said casing member of smaller area than the rest of the casing member.

7. The combination of an aerosol container body and the valve assembly defined in claim 1 wherein said casing member is a cap, said container body and said cap being sealingly joined together to form an aerosol container.

l IF I k hated m l 7, '1 973 Patent No. W 3 a 1 Kenneth Wilmot Inventofls) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the 'cover sheet insert [50] Foreign Application Priority Data Great Britain May 19, 1971 15,902/71 Signed and sealed this 12th day of November 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Ofificer Commissioner of Patents F ORM PO-I 050 (10-69) USCOMM-DC 603764 69 uvs Gov/taunt!" rnnmuo orncz: 930 

1. A valve assembly comprising a casing member adapted to form at least the top portion of an aerosol container, a hollow body secured to the inside of said casing member, an elongate valve member sealingly extending through respective apertures in said casing member and said hollow body for longitudinally inward movement during a dispensing operation from an outer position with respect to the casing member, means defining outlet and inlet passages in said valve member adjacent to the outer and inner ends thereof, respectively, and operative for connecting a chamber formed by the space inside said hollow body around said valve member with the outside and inside, respectively, of said container and arranged such that in said outer position only the inlet passage is operative and such that when said valve member is moved by more than a predetermined amount inwardly the inlet passage becomes non-operative and the outlet passage becomes operative, a second hollow body having one end closed and secured to the inner end of said valve member, said second hollow body enclosing said first hollow body and forming a capillary gap between the two bodies which, in said outer position, extends along said first hollow body from near the position where it is secured to said casing member to said aperture therein, whereby said inlet passage in the valve member, in such position, communicates said chamber with the inside of said container via said capillary gap.
 2. The valve assembly defined in claim 1 wherein said first hollow body has a cylindrical external configuration and said second hollow body has a cylindrical internal configuration whereby said capillary gap includes an elongate annular portion.
 3. The valve assembly defined in claim 2 wherein said valve member is arranged coaxially with said first and second hollow bodies and said aperture in said first hollow body is located centrally of an inner end closure.
 4. The valve assembly defined in claim 3 wherein said second hollow body has a portion of reduced diameter at the inner end thereof inside which said inner end of said valve member is fitted.
 5. The valve assembly defined in claim 1 including means defining the stroke of said longitudinal movement of said second hollow body during a dispensing operation, said stroke and the internal area of said second hollow body being such that during dispensing the increased space defined between said first and second bodies is at least of the same order of volume as said chamber, whereby liquid drawn through said capillary gap and into said increased space during inward movement of said second hollow body will be urged into said chamber and fill at least the major portion of the chamber upon outward movement of said second hollow body.
 6. The valve assembly defined in claim 1 wherein said first hollow body is secured to an outwardly extending portion of said casing member of smaller area than the rest of the casing member.
 7. The combination of an aerosol container body and the valve assembly defined in claim 1 wherein said casing member is a cap, said container body and said cap being sealingly joined together to form an aerosol container. 